   [1 2 3] => (has-prefix   [2 1]) ; false - order matters
   [1 2 3] => (has-prefix   [2 1] :in-any-order) ; true
   [1 2 3] => (has-prefix  #{2 1}) ; true "
-        :arglists '([expected-prefix looseness?])}
+        :arglists '([expected-prefix]
+                    [expected-prefix looseness?])}
     has-prefix
     (container-checker-maker 'has-prefix
       (has-xfix "prefix" #(re-pattern (str "^" %)) take)))

   [700 4 5] => (contains #{4 5 700})

:gaps-ok can be used with a set. (So can :in-any-order, but it has no effect.)"
    :arglists '([expected looseness])}
    contains (container-checker-maker 'contains
               (fn [actual expected looseness]
                 (let [[actual expected looseness] (standardized-arguments actual expected looseness)]


  [1 3 2] => (just   [1 2 3] :in-any-order)
  [1 3 2] => (just  #{1 2 3})"
         :arglists '([expected]
                     [expected looseness])}
    just (container-checker-maker 'just
           (fn [actual expected looseness]
             (let [[actual expected looseness] (standardized-arguments actual expected looseness)]
